Display device with molded light guide

ABSTRACT

A display device includes a base with at least one light device. A conductive layer is provided on the base and is electrically coupled to the light device. A light guide is formed the base and the conductive layer, and includes an aperture surrounding the light device and having a profile for directing light from the light source outwardly from the base.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority as availableunder 35 U.S.C. 119 (e)(1) of U.S. Provisional Patent Application No.60/406,434 titled “Display Device” filed on Aug. 28, 2002 and U.S.patent application Ser. No. 10/608,667 titled “Display Device” filed onJun. 27, 2003 (the entire disclosures of which are incorporated byreference).

FIELD

The present invention relates to a display device. The present inventionrelates more particularly to a molded light guide for use in displaydevices with printed circuit boards and light sources.

BACKGROUND

The use of optoelectronic devices with light guides for dispersing orfocusing the light from bulbs or other light emitting devices isgenerally known. Such guides may be provided on printed circuit boardshaving groupings or arrays of LEDs or other light emitting devices forproviding displays such a sign or message board assembly. However, theknown light guides are often susceptible to problems associated with thephysical attachment of the light guide to the printed circuit board. Forexample, the electrical interconnections between the light source andthe circuit board are typically delicate and may be easily damagedthrough the handling and installation of the light guide onto thecircuit board. Also, gaps are often present between the light guide andthe circuit board, resulting in leakage of the emitted light along thesides of the circuit board. Also, the application of a molded lightguide to a printed circuit board has typically resulted in warping orphysical distortion of the assembly. Further, providing an array of LEDson a printed circuit board and attaching a light guide for use indisplays often results in individual LEDs within the array havingvarious degrees of uniformity in color and brightness, thus leading todisplay images having less uniformity in the optical performance of thedevice than desired.

Accordingly, it would be advantageous to provide a display device havingone or more of the following features alone or in combination with oneor more of the other features: a light guide that is molded to a printedcircuit board for developing a desired light emission profile, a lightguide that is adhered directly to a printed circuit board to minimizelight leakage and avoid the use of external attachment devices such asadhesive tape, a light guide that does not require a degassingoperation, a light guide that does not result in warping or physicaldistortion of the assembly, a light guide that provides protection forelectrical interconnections and components to create a more robustassembly, a light guide that upon assembly can be separated intoindividual pixels for matching and grading uniformity and performance ofthe individual pixels for assembly into a display unit, or a light guidethat may be used as an optical coupling device.

SUMMARY

One aspect of the present invention relates to a display device andincludes a base with at least one light device, a conductive layerprovided on the base and electrically coupled to the light device, and alight guide formed on the base and the conductive layer, and having atleast one aperture surrounding the light device.

Another aspect of the present invention relates to a display devicehaving a base with at least one light source, and a layer of materialdisposed on the base and having at least one aperture defining a profilewith the light source for directing light from the light sourceoutwardly from the base.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a display device according toa preferred embodiment.

FIG. 2 is a perspective view of a display device according to apreferred embodiment.

FIG. 3A is a top view of a display device according to a preferredembodiment.

FIG. 3B is a cross section view of the display device along line 3B-3Bof FIG. 3A, according to a preferred embodiment.

FIG. 4 is a top view of a display device separated into pixels accordingto a preferred embodiment.

FIG. 5A is an exploded perspective view of a pixel of the display deviceof FIG. 4 according to a preferred embodiment.

FIG. 5B is a perspective view of a pixel of the display device of FIG. 4according to a preferred embodiment.

FIG. 5C is a cross-sectional view of an individual pixel of the displaydevice along line 5C-5C of FIG. 5B according to a preferred embodiment.

FIG. 6 is a rear perspective view of an application of the displaydevice according to a preferred embodiment.

In the various drawings, like reference numerals are used to indicatelike components.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a display device 10 is shown. Display device10 may be used to transmit light images or information to humanobservers, such as for use with display assemblies such as signs,message boards, information displays, etc. for providing lighting,alphanumeric messaging, imaging or signaling (e.g. device-to-eyeapplications). Display device 10 may also be used as an interface totransmit/receive light images or information to non-human observers,such as for use with optical couplers and equipment interfaces (e.g.device-to-device, fiber-to-fiber, fiber-to-device, or device-to-fiberapplications). The display device is adapted for use as an assembly thatincludes an array of pixels (as shown schematically in FIG. 2), and foruse as an individual pixel (as shown schematically in FIGS. 5A-5C) or anassembly of individual pixels.

Display device 10 includes a base member (shown schematically as asubstrate material 20), a conductive material provided thereon forming acircuit pattern, light devices 22 such as a light receiving device or alight transmission source (such as a visible light source, shownschematically as LEDs in FIGS. 5A-5C, an infrared light source, etc.)and a guide member (shown as light guide 30) having an inward surface 32adapted to overlay and be molded onto substrate 20, and includingapertures 40 adapted to guide the light emitted from the light source 22(or received from other sources when used as an optical coupler). Acontrast coating 14 is provided on an outward surface 34 of molded lightguide 30 to provide a contrasting background to the light source 22. Acoating layer 16 (e.g. a seal, sealant, lens, or an optical coatinglayer having characteristics that are transparent, semi-transparent,colored, etc.) may be provided on the outward surface 34 of molded lightguide 30 and contrasting coating 14 to provide a desired optical imagingwhen viewing display assembly 10. In other embodiments, a pottingmaterial (e.g. epoxy, etc.) may be used to fill the volume within theapertures and a coating layer may either be included or omitted. Thepotting material may be an optical diffusant or a colored material toprovide the desired “output” or “input.”

Referring further to FIGS. 1 and 2, the substrate 20 has a conductivematerial 25 (see FIG. 5C) provided thereon (e.g. overlayed, embedded,etc.) to form suitable circuitry 26 for providing electricalconductivity (e.g. anode, cathode, etc.) to an array of light sources(shown schematically as LEDs 22 in FIGS. 5A-5C) that are positionable onthe conductive material of substrate 20. Each light source may be asingle light source or may be a plurality of light sources (e.g.multiple LEDs, etc.). The conductive material may be gold, silver,aluminum, or other suitable conductor for providing circuitry on thesubstrate. Light sources 22 may be formed of any suitable material toprovide light of various colors and intensities suited for the intendedapplication. The light sources may also be configured and controlled tocombine or mix the color of the light emitted to provide other lightcolors.

In a preferred embodiment, the light sources are LEDs that are providedin a sixteen (16) by sixteen (16) array and the substrate isapproximately seventy-one millimeters in length and approximatelyseventy-one millimeters in width, with a thickness of approximately 0.5millimeters. The LEDs are attached to the conductive material 25 ofsubstrate 20 by a die attachment method, such as with silver epoxyconductors, or by other suitable methods. The LEDs may be discrete colorLEDs configured to emit light in a single color (e.g. monochromatic),such as white, red, green or blue, or multicolor LEDs (e.g. red, greenand a mixture of red and green to create amber) or may be any suitablecombination of LEDs of individual colors to provide the desired displayimage on display device 10. In a preferred embodiment, substrate 20 ismade of a ceramic material for providing electrical insulation forcircuitry 26 and to provide suitable heat transfer for heat generated bythe light sources, but may be made of any suitable material such asphenolic, fiberglass, paper or other conventional types of materialscommonly used in circuit board applications. The substrate 20 includesinterfaces (shown schematically as openings or cylindrical apertures 24in FIG. 5C) positioned around the LEDs 22 and extending throughconductive material 25 and substrate 20. The conductive material 25extends along a wall of cylindrical apertures 24 to provide electricalcontinuity to conductive pads 27 located on the bottom of substrate 20(see FIG. 5C). The conductive pads 27 are positioned to provideelectrical contacts suitable for engaging other circuit components (e.g.of a conventional type) for use with the display device such as printedcircuit boards, etc. for communicating with the light source on the topof the substrate. Cylindrical apertures 24 also provide structureintended to enhance securing the light guide 30 to the substrate 20 (tobe further described). In a preferred embodiment, the cylindricalapertures 24 are provided as four apertures that are spaced around theoutside of each light source. The LEDs may be any conventional LEDadapted for mounting on a substrate and may be provided in any suitablecolor to provide the intended optical image from the display device. Inalternative embodiments, the substrate may have any suitable size, shape(e.g. rectangular, etc.), thickness and any suitable number of LEDs orother light sources such as infrared may be provided in any patterndesired to suit the intended display device application.

Referring further to FIGS. 3A-3B, the light guide 30 is shown as agenerally planar member having an array of apertures 40 positioned tocorrespond to the location of the light sources such as LEDs 22 on thesubstrate 20, such that each LED is surrounded by an aperture 40 on thelight guide 30. The light guide 30 is made of a material such as aplastic-based material that may be formed in a suitable molding processand provides the desired light reflection or absorption qualities forthe intended display application. The light guide material is selectedto provide suitable performance characteristics such as a melting pointgreater than the heat generated by the light source so that the lightguide material will not deform during operation. In a preferredembodiment, the light guide 30 is formed by molding the light guidematerial onto the surface of the substrate 20 and conductive material25, whereby the light guide material enters or “flows” into thecylindrical apertures 24 on the substrate 20 to enhance securing thelight guide 30 onto the substrate in the vicinity of each of the lightsources. Application of the light guide material directly on to thesubstrate is intended to provide a seal between the light guide andsubstrate (e.g. a hermetic seal, etc.). In a particularly preferredembodiment, the light guide material is plastic having a generally whitecolor that is formed onto substrate 20 in an injection molding process,such that the thickness of the light guide is approximately one (1)millimeter. In an alternative embodiment, the light guide may be securedto the printed circuit board using other configurations, such asstructure (e.g. ribs, ridges, posts, etc.) extending from the printedcircuit board, or a light guide material that adheres to the surface ofthe substrate, or adhesive, etc. In other alternative embodiments, thelight guide may be formed of other material compositions and colors, inany desired thickness, or by other suitable molding processes.

Referring further to FIGS. 3A-3B, the apertures 40 in the light guide 30are formed with a side wall 42 to create a light emission profileconfigured to guide or focus the light emitted from each of the lightsources. In a preferred embodiment, the light emission profile of theside wall 42 is in the shape of a truncated cone with a first (e.g.“narrow”) portion 44 having a diameter of approximately 2.4 millimetersand oriented inwardly and surrounding the LED 22, and a second portion(e.g. “wide”) 46 having a diameter of approximately 3.2 millimeters andoriented outwardly, where the side wall 42 forms an angle Φ from areference line extending perpendicularly outwardly from the printedcircuit board 20. The angle Φ may be formed at any suitable angle toprovide the desired emitted light leakage quantities and peripheralreadability characteristics for the intended display device application.The shape of the light emission profile of side wall 42 and the angle Φare selected to optimize the emission of light for a particularapplication. For example, angle Φ may be relatively narrow fornon-visible light applications (e.g. infrared, etc.) and may berelatively wider for visible light applications. In a particularlypreferred embodiment, the angle Φ is approximately within the range of20-25 degrees, but may be within any suitable range to optimize theemission of light for an application. The shape of the light emissionprofile of the side walls may be in shapes other than a truncated cone.For example, the light guide may be formed with side walls having aparabolic shape (e.g. cup-shape, etc.) to provide increased or modifiedreflective light emission or to provide a desired light reflectionpattern. For example, the pattern may be adjusted to increase the lightsignal to noise ratio, or reduce the light signal to noise ratio, or tominimize cross-talk or interference of the light signals from adjacentlight sources. In an alternative embodiment, the shape of aperture maybe non-circular (e.g. oval, elliptical, etc.) to provide the desiredlight transmission or reception profile.

The space within the aperture 40 may be unfilled (e.g. air space), ormay be filled with an encapsulating or fill material (e.g. potting,etc.) for sealing and enhancing the optical image (e.g. intensity,color, color mixing, etc.) of light source 22. In a preferredembodiment, a fill material 45 shown schematically as a clear epoxy isprovided that enhances the durability of the display assembly 10 andprovides the desired optical emission of light from the light source.The fill material may be allowed to cure under ambient conditions or maybe oven-cured to expedite manufacturing processing time. The fillmaterial may result in a surface that is concave (as shown schematicallyin FIG. 5C) or may be generally flat of convex, as necessary to providethe desired optical performance. According to any preferred embodiment,the seal provided between the light guide and the substrate permits thefill material to be applied from the outward surface 34 (e.g. “front”)of light guide 30, rather than applying the fill material from an inward(or “back”) side of the light guide as is typically necessary inconventional display applications. In an alternative embodiment, theapertures may have side walls configured at other angles suitable forproviding the desired light emission qualities, or the side walls may beformed in a cupped or parabolic shape, and the fill material may be anysuitable material for encapsulating the light source within the apertureand may be provided in any suitable color for providing the desiredoptical image. In another alternative embodiment, the light guide mayalso be adapted for use in applications where light is received by thecircuitry on the substrate. For example, the light guide may be appliedover a substrate or printed circuit board that is adapted to interfacewith light signals from a source (e.g. from fiber optic sources, etc.),in which the aperture acts as a lens to direct light from the source tothe printed circuit board.

Referring to FIGS. 1 and 5A, a contrast coating 14 (e.g. a layer or filnof ink or other suitable pigment or coloration, etc.) may be provided onthe outward surface of the light guide 30 according to a preferredembodiment. The contrast coating 14, if used, is applied to the surfaceof the light guide 30 to provide a contrasting background for viewingthe light images emitted from the light source(s) 22 (shown as LEDs) onthe display device 10. Contrast coating 14 may be applied in anyconventional manner such as screen printing and provided in a color suchas black, or other suitable contrasting color to suit an intendeddisplay application. Another coating 16 (e.g. tape layer, adhesivepanel, lens, etc.) may be provided over the contrast coating 14 to sealthe apertures 40 and to improve optical uniformity of the light emittedfrom the light source. Such coating 16 may be substantially transparent,such as for single LED or may be semi-transparent, such as for amulticolor LED or for multiple single-color LEDs to provide acolor-blending effect. Coating 16 may also be provided in various colorsto act as a lens through which the emitted light from the light sourceis viewed. The assembled display device 10 provides a plurality ofindividual cells or pixels 50 (shown schematically in FIG. 4B) that areformed by the light source 22 (shown as LEDs) and the respectiveportions of the substrate 20, conductive material 25, light guide 30,contrasting coating 14 and coating 16. In an alternative embodiment, thecontrast coating and the top coating may be combined into a singlecoating layer for application on the light guide. In another alternativeembodiment, the contrast coating may be applied by other methods such asinkjet printing, screen printing or digital printing.

Referring to FIGS. 2 and 4, the display device 10 may be used as asingle component or separated into multiple display components accordingto a preferred embodiment. As shown in FIG. 2, the assembled displaydevice may be used as a single display assembly and may be provided in asufficient size with a sufficient number of LEDs to suit a particulardisplay device. Display device 10 may be made as a large unit or boardand segregated into smaller elements for use in smaller sign or displayapplications.

Referring to FIG. 4, the display device 10 may be separated into smallergroups of pixels or into individual pixels by separating the displaydevice 10 into subgroups of pixels or into individual pixels. Thecomponents of the display device may be made in any suitable size toprovide pixels having any desired size, intensity, and lighttransmission/reception characteristics. In one embodiment, the pixelsare separated by cutting the display device 10 along one or more lines48 between the apertures 40. Such cutting of the display device 10 intoindividual pixels or groups of pixels may be performed by a dicing sawhaving a diamond cutting wheel in a semi-automatic or fully automatedoperation, or the cutting operation may be accomplished by a lasercutting techniques. In an alternative embodiment, the pixels may beseparated into subgroups or individual pixels by any suitablenon-destructive separation or cutting operation that does not damage thepixels.

Referring to FIGS. 5A-5C an individual pixel of a display device isshown according to a preferred embodiment. The pixels include acorresponding portion of the substrate 20, the conductive material 25,the light guide 30, the light source 22 (shown as an LED), anencapsulating material 45, the contrast coating 14 and (if provided) acoating 16. As shown in FIGS. 1 and 5C, substrate 20 has a conductivematerial 25 on a top surface that provides conductive regions (e.g.traces, patterns, etc.) of circuitry 26 for providing conductivity withthe light sources 22 (shown as LEDs). The conductive material on the topof the substrate extends through aperture 24 and provides continuitywith conductive pads 27 on the bottom of substrate 20. In a preferredembodiment, four apertures 24 are configured at each corner of the pixeland are each configured to provide continuity to one of four conductivepads at the corners of the pixel that correspond to four conductiveregions of circuit 26 for use with three individual LEDs provided as alight source. Each LED is electrically interconnected to the appropriateregions of circuit 26. In a preferred embodiment the anode of each LEDis attached to a respective conductive region of circuitry 26 by silverepoxy and the cathode of each LED is attached by a wire 29 to a commonconductive region of circuitry 26. The conductive regions of circuitry26 may be configured for placement of the light source(s) approximatelyat the center of aperture 40 of the light guide 20 to provide improvedoptical performance of the display device. Placement of the lightsource(s) at the approximate center of the light guide also tends tominimize the length of the wires used for electrical interconnection ofthe light source(s), which is believed to reduce the tendency of thewires to break during high temperature application or usage. Theplacement of the light source within aperture 40 may be substantiallynon-centered for applications as necessary to develop desired lightemission or reception profiles. Conductive pads 27 provide contactlocations for suitable connecting circuitry used to control (e.g. drive,modulate, etc.) the light sources (such as by printed circuit boards,etc.).

In a preferred embodiment, the individual pixels 50 are individuallytested and graded according to established operating criteria andperformance standards (e.g. conductivity, brightness, color, clarity,etc.) and “binned” or segregated into groups having like or similarperformance characteristics. The segregated groups of pixels may then beused to assemble signs, displays or message boards comprised ofindividual pixels having relatively uniform and consistent displaycharacteristics, or for positioning lower grade pixels in certain areasof the sign, display or message board that are more optically oraesthetically acceptable. The segregated groups of pixels may also beassembled into graded pixels blocks (having any suitable number ofpixels of like or otherwise desirable performance characteristics) thatmay then be assembled as components of larger signs, displays or messageboards having the desired pixel performance and display qualities. Suchseparated display device portions, individual pixels or pixel blocks maybe used for rapidly assembling custom-order signs, displays or messageboards without having to specially create a new display device for eachnew application.

Display device 10 may be formed as an individual unit for use in variousLED display devices, alphanumeric message boards, signs, etc. including(by way of example) taxiway signs or signs for transportation depots orfacilities (e.g. airports, railway stations, bus stations, ports,highways, etc.), having suitable software for displaying multilingualmessages, retrofit LED display boards for drop-in display modules thatreplace or supplement conventional display signs or provide enhancedmessaging or imaging capability with existing displays in commercial(restaurants, stores, shopping centers, etc.), industrial (factories,offices, manufacturing and assembly facilities, etc.), institutional(schools, libraries, hospitals, etc.) or governmental facility signageor display applications. Such display devices may also be used in one ormore arrays for residential applications, such as to provide lighting(e.g. normal or emergency), in which the circuitry is suitably coupledto a circuit device (not shown) for converting standard residentialelectrical power, such as 120 volts AC and 60 hertz, or from a back-upsource, to a suitable power level adapted for use by the display device.

The structure of the display device may be used in other applicationsfor transmitting and receiving light. For example, the light guide maybe used as an integral component with any optoelectronic device. Thelight guide, substrate, and suitable circuitry may be configured asmating halves of a coupler (e.g. plug, connector, interface, etc.) forcoupling, modulating or amplifying light signals between variousdevices. For example, a “plug” having suitable light transmission orreceiving structure, or electrical conductivity device, may be moldedonto the top or bottom of the display device and configured tointerconnect with other pugs or devices. The light guide may also beused with suitable substrates and circuitry for night visionapplications and for coupling of fiber optic devices. In fiber opticapplications, the light guide may be used as an optical coupler for usein “plugs” or connectors configured to fit together for transmitting andreceiving light signals among various equipment.

Display device 10 may also be used for upgrading existing displays orsignage or for providing additional display capabilities by sizing thedisplay assembly 10 for use as a “drop-in” replacement for an existingsign, panel or display, particularly in applications that wouldotherwise require application for a new “permit” or other authorizationwhere necessary for use of a new or replacement sign or display.Additionally, multiple display assemblies may be grouped together andcoordinated with suitable messaging or imaging software to providealphanumeric or imaging displays (e.g. single color or multicolor) forlarge scale signs, such as (by way of example) large displayapplications including stadium scoreboards, electronic billboards, videodevices, viewing screens and the like.

Referring to FIG. 6, display device 10 may further be used to providesignal devices (shown schematically as a vehicle signal 60 for a vehicle62, but may include other signal applications such as airport runwaysignals, highway traffic signals, railway crossing signals, other visualindication signals, etc.). Such signals may be provided with, orassembled from pixels or pixel arrays having, various LED configurationsadapted to emit light having different colors according to the differentfunctions of the signal. In one embodiment, signal 60 includes, or iscoupled to, control circuitry (not shown) of a type that is responsiveto a vehicle user's actions to actuate the signal 60 to emit light fromLEDs 22 in a first color (e.g. red) during braking, or a second color(e.g. amber) during turn-signaling or hazard signal operation, or athird color (e.g. white) during operation of vehicle 62 in a reversedirection. The control circuitry may be configured such that signal 60may provide indication for one or more functions separately and may alsobe configured to provide indication for one or more functionssimultaneously. For example, signal 60 may indicate multiple functionssimultaneously by alternating the emitted light color according to thecorresponding functions on a predetermined time interval, or the displayof the signal 60 may have several portions, each configured to provideindication of a particular function. Alternatively, signal 60 mayindicate multiple functions simultaneously by alternating the emittedlight color of certain groups of the LEDs 22 on the display device 10 tocreate a desired pattern for a first function, such as a directionalsignal, interposed on a desired pattern for a second function such as abrake signal. In a similar manner, multi-portion traffic lights may bereplaced with a single portion having an array of multicolor LEDS or arange of discrete color LEDs. This arrangement would permit merelychanging the color portion rather than having three separate portions asare currently used. This arrangement would also permit displaying analphanumeric message or graphic image in the traffic light signaldisplay portion.

Signal 60 according to the embodiment may be provided as a substantiallyflat panel display device adapted for installation on a surface, such asa vehicle panel 64, without the necessity for wells, recesses orcompartments in the body of vehicle 62 as are typically required forconventional vehicle signal devices. Such surface installation mayprovide increased space within the interior of vehicle 62 and reduce thecomplexity and time associated with vehicle panel forming operations andassembly activities. Of course, signal 60 could be positioned in asimilar manner as are conventional light bulbs by placing them in ahousing under a lens or transparent cover.

According to any preferred embodiment, the display device includes asubstrate material (such as ceramic, etc.), having a conductive material(such as gold, etc.) provided thereon in a suitable pattern to provide acircuit board configured to interface with one or more light sources anda control circuit (e.g. external). A moldable material is molded ontoone or both of the substrate and conductive material to provide a lightguide that surrounds a portion of the circuitry that is adapted formounting one or more light sources thereon. The substrate may havesuitable structure (such as apertures) intended to improve the adhesionof the light guide to the substrate. One or more light sources (such asLEDs) are installed on the substrate and electrically interconnected tothe appropriate portions of the circuitry (e.g. by conductive epoxy,wires, etc.). If desired, the light sources may be encapsulated withinthe light guide by a suitable material (e.g. epoxy, etc.).

According to any preferred embodiment, the display device may bemanufactured by providing a substrate material, providing a conductiveoverlay material to form the desired circuit patterns thereon, molding alight guide onto the substrate and conductive material, installing thelight source(s) on the appropriate portion(s) of the circuit patterns,installing the electrical interconnections between the light source(s)and the appropriate portion of the circuit pattern, encapsulating thelight source(s) within the light guide. If desired, the display devicecan be separated (e.g. cut, sawed, diced, etc.) into individual pixelsthat may be graded and “binned” for use in assembling graded pixelblocks. The formation of the light guide on the substrate and/or theconductive material prior to installing and electrically interconnectingthe light source(s) is intended to improve the durability and ruggednessof the device. Further, the installation of the encapsulating materialafter electrical interconnection of the light sources is also intendedto improve the durability and ruggedness of the device.

It is important to note that the construction and arrangement of theelements of the display device provided herein are illustrative only.Although only a few exemplary embodiments of the present invention havebeen described in detail in this disclosure, those skilled in the artwho review this disclosure will readily appreciate that manymodifications are possible in these embodiments (such as variations ininstallation location and orientation, sizes, structures, shapes, anglesand proportions of the various elements, mounting arrangements, use ofmaterials, combinations of shapes, etc.) without materially departingfrom the novel teachings and advantages of the invention. For example,the light guide may be used in any application for directing, focusingor dispersing the light emitted from a display, sign, message board orother light transmitting or receiving system. Also the light guide mayhave any suitable shape, length, thickness, location or orientation foruse in connection with manufacturing large arrays of light sources suchas, but not limited to, LEDs and separating the large array into groupsof smaller arrays. Additionally, the light guide may be used with anysuitable light emitting device surface other than printed circuit boardshaving LEDs. The light guide may be used to control the outward emissionof light from the LEDs, or may be used to receive light from a source(e.g. fiber optics source, etc.) configured to interface with a printedcircuit board. Further, it is readily apparent that the light guide maybe provided in a wide variety of shapes, sizes, thickness, and lightdistribution profiles and adapted for installation on any size printedcircuit board. Additionally, the sign, message board, imaging screen orinformation display may be any display adapted to visually conveyalphanumeric messages, signals, information or images for use inoriginal design applications or for use in retrofit applications forreplacing, enhancing or upgrading existing signs or display devices.Accordingly, all such modifications are intended to be within the scopeof the invention.

While the present invention has been described in connection with aparticularly preferred embodiment thereof, the invention is not to belimited by the drawings. The order or sequence of any process or methodsteps may be varied or re-sequenced according to alternativeembodiments. In the claims, any means-plus-function clause is intendedto cover the structures described herein as performing the recitedfunction and not only structural equivalents but also equivalentstructures. Other substitutions, modifications, changes and omissionsmay be made in the design, operating configuration and arrangement ofthe preferred and other exemplary embodiments without departing from thespirit of the inventions as expressed in the appended claims.

1. A display device, comprising: a base; at least one light devicecoupled to the base; a conductive layer provided on at least a portionof the base and electrically coupled to the light device; and a lightguide formed on the base and the conductive layer, and having at leastone aperture surrounding the light device.
 2. The display device ofclaim 1 wherein the base includes at least one opening configured toreceive a material used in the formation of the light guide.
 3. Thedisplay device of claim 2 wherein the opening is a plurality ofcylindrical openings disposed adjacent the light source.
 4. The displaydevice of claim 2 wherein the conductive layer extends at leastpartially through the opening.
 5. The display device of claim 2 whereinthe light guide is molded in a securing relationship with the opening.6. The display device of claim 1 wherein at least one conductive pad isprovided on an underside of the base and configured to provideelectrical connectivity with the light device.
 7. The display device ofclaim 1 wherein the conductive layer provides a circuit.
 8. The displaydevice of claim 7 wherein the circuit includes a cathode and at leastone anode for connecting the light device.
 9. The display device ofclaim 8 wherein the light device is substantially centered within theaperture.
 10. The display device of claim 1 wherein the aperture isdefined by side walls having a truncated cone shape.
 11. The displaydevice of claim 1 wherein the light device is a single color LED. 12.The display device of claim 1 wherein the light device is a multicolorLED.
 13. The display device of claim 1 further comprising a contrastingcoating provided on the light guide.
 14. The display device of claim 1further comprising an optical coating.
 15. The display device of claim 1wherein the light device is encapsulated within the aperture by a fillmaterial.
 16. The display device of claim 1 wherein the display assemblyis a one of a sign, a display panel and a message board.
 17. The displaydevice of claim 1, wherein the display assembly is adapted to provide amessage in a first language and a second language.
 18. The displaydevice of claim 1, wherein the display assembly is a retrofit displayassembly adapted to replace an existing display.
 19. The display deviceof claim 1, wherein the display assembly is a taxiway sign.
 20. Adisplay device, comprising a base with at least one light source atopthe base, and a layer of material disposed on the base, the layer ofmaterial having at least one aperture surrounding the light source anddefining a profile for directing light from the light source outwardlyfrom the base.
 21. The display device of claim 20 wherein the baseincludes at least one opening configured to receive a portion of thelayer of material.
 22. The display device of claim 20 wherein theprofile comprises a truncated cone shape.
 23. The display device ofclaim 20 wherein the profile comprises a parabolic shape.
 24. Thedisplay device of claim 20 further comprising a conductive materialdisposed on the base to provide a circuit configured for electricalconnection with the light source.
 25. The display device of claim 24wherein the base and the conductive material are configured to form acircuit board.
 26. The display device of claim 20 wherein the lightsource is an LED.
 27. The display device of claim 26 wherein the LED isa multicolor LED.
 28. The display device of claim 26 wherein the LED isa monochromatic LED.
 29. The display device of claim 20 furthercomprising a fill material disposed within the aperture.
 30. The displaydevice of claim 20 wherein the light source comprises a plurality oflight sources, and the base and the layer of material and the lightsources are configured for separation into a plurality of pixels. 31.The display device of claim 30 wherein the plurality of pixels areconfigured for separation by a dicing saw.
 32. The display device ofclaim 30 wherein the pixels are evaluated to establish a grade accordingto a set of performance characteristics.
 33. The display device of claim32 wherein the pixels are grouped into one or more groups according tothe grade.
 34. The display device of claim 33 wherein the pixels fromone of the one or more groups are assembled into one or more displayblocks of the pixels.
 35. The display device of claim 34 wherein the oneor more display blocks of the pixels are assembled into a displayassembly.
 36. The display device of claim 35 wherein the displayassembly is one of a sign, a message board and an information display.37. The display device of claim 35 wherein the display assembly is aretrofit display assembly.